Question: In 45 years, William will be 4 times as old as he is right now. How old is he right now?
Solution: We can use the given information to write down an equation about William's age. Let William's age be $w$ In 45 years, he will be $w + 45$ years old. At that time, he will also be $4 w$ years old. Writing this information as an equation, we get: $w + 45 = 4 w$ Solving for $w$ , we get: $3 w = 45$ $w = 15$.